Until now the depth control of the torpedo has been based only on the detecting of the depth and angle of attack of the torpedo. However, a control system of this kind is unsatisfactory for a torpedo with the facility to vary its speed during its course, because it is associated with depth errors during the speed variation period. This is attributable to the fact that all angle of attack sensors of the aforementioned types are sensitive to acceleration. During variation of the speed, acceleration forces will accordingly influence the behaviour of the torpedo. In the case of an increase in speed, but without any change in depth, the angle of attack sensor will thus transmit a signal corresponding to the signal which is transmitted when the torpedo is rising. The regulator would, if nothing were to be done to counter that effect, cause the torpedo to dive in order to achieve the normal angle of attack.